Portable hydraulic hoist or movable scaffold



.Dec. 19, 1939. D. R. mus 2,183,679

PORTABLE HYbRAULIC HOIST OR, MOVABLE SCAFFOLD Filed July 12, 1938 I 4 Sheets-Sheet 1 INV ENT OR.

ATTORNEY.

Dec. 19, 1939. D. R.- HILLIS 2,183,679

PORTABLE HYDRAULIC HOIST 0R MOVABLE SCAFFOLD Filed July 12, 1958 4 Sheets-Sheet 2 INVENTOR. 0/91/10 I? fill. IJ.

ATTOR EY. I

Dec. 19, 1939. D. R. l-ilLLIS I 7 PORTABLE mmmuuc HOIST 0R MOVABLE SCAFFOLD Filed July '-12 1938: 4 Sheets-Sheet s INVENTOK flmr/o f2 MIA/J.

Patented Dec. 19, 1939 UNITED STATES PORTABLE HYDRAULIC HOIST on MOVABLE soar-row.

David R. Hillis, Detroit, Mich, assignor, by mesne assignments, to Reconstruction Finance Corporation, Detroit, Micln, a corporation of the United States Application July 12, 1938, Serial No. 218,888

'7Claims.

My invention relates to a movable scaffold and includes a platform adjustable in position vertically and horizontally by an operator on said platform, and byap'paratus located at a lower 5 level. The vertical adjustment is by hydraulic power.

In the accompanying drawings: v Fig. 1 is a plan view of an apparatus embodying my invention;

.10 Fig. 2 is.a side elevation looking from below Fig. 1, the platform being in its lower position;

. Fig. 3 is an elevation looking from the left of Figs. 1 and 2, the platform being raised;

Fig. 4 is a sectional elevation to an enlarged 18 scale, broken away, intermediate its ,upper and lower ends and at the right hand side to economize room;

' Fig. 5 is a sectional elevation of the part of the construction broken away at the right in Fig. 4;

2 Fig. 6 is a detail section on the line 66 Fig.

modified structure where duplicate positioning apparatus are used, shown in a portion of a room;

80 Fig, 12 is an elevation looking from the right of Fig. 1-1, to a reduced scale; and

Fig. 13 is a detail section on the line I3-I3 Fig. 11, to an enlarged scale.

I is a supporting platform, or supporting base, 86 of sufficient breadth at its end Ia, its sides converging toward an intermediate point2 and extending in a girder-like arm I to the other end, lb. 44 are supporting wheels at oppositesides of the platform. At the end In thereof (Fig. 3) 40 is a tube 5 extending across the platform I beneath its end Ia. 5a5a are stub axles for the wheels 4-4 which extend into the ends of the tube 5 and slide out and into said tube to adjust the wheels 4-4 to different distances apart,

45 to pass through a doorway, or to prevent the tipping of the scaffold when in raised position.-

' They may be secured in adjusted position in any suitable manner. 6 is a wheel supporting the end lb of the platform I. The wheel 8 is adapt- 50 ed to turn about a vertical axis as hereinafter described. I

, 'I--I are standards extending upward from the .platform I at points adjacent to its comers at its end la. 8 is atube extending vertically up- 55 ward from the platform I at the point 2 to which its sides converge. The wheel 6 (Fig. 5) has its axis bearing in the lower ends of the branches of a fork 6a which fork has a hub, or arbor, 9 fixed in the outer end of the arm 8 so as to turn about a vertical axis. 5

I0 is atube, square in cross-section as shown in Fig. 7, having its lower end fixed to the upper end of the hub 9 and extending upward to a point a little below'that of the operating mechanism of the apparatus. 10

I I is a framework adapted to slide vertically on the uprights 'II, and carrying the platform I2 upon which the workman stands. 3

I3 indicates rods extending horizontally from a standard I and the corresponding part of the frame I I, serving as rounds of. a ladder by which a workman may mount to the platform I2.

I4 is a transverse girder extending between the side pieces of the frame II, at the top thereof and I5 is a cantilever arm extending from the center of the girder I4 to a point just above the tube Ill.

The tube 8 extends upward from the point 2 of the platform I, to a point just below the center of the girder I4 where the arm I5 joins it, when the platform is in its lowest position. The tube 8, at that time, passes through an arcuate opening in the platform I and is provided with a drainage opening 8a at its lower end, as shown in Fig. 4. I1 is a tube flxed at its upper end to the girder I4, extendingdownward therefrom and so fitting and adapted to slide in thetube 8. The lower end of the tube IT is closed.

I8"is.a pump inthe upper end of the tube II, having a plunger I9 extending above the g'irder' I4. I80 is the suction, or intake, pipe of the a pump I8 open at the lowerend in the tube I1.

20 is a'casting closing the upper end of the tube I1 and forming the head of the pump I8. There 'is a cavity 2| formed in the head 20.

22 is the discharge pipe of thepump I8 leading to and 0 .opening into the cavity2I in the pump head 20.

The cavity 2I opens through a passage 23 to the interior of the cylinder of the pump I8 and through said cylinder and a passage 24 to the interior of the tube I1. 25 is a pipe leading from the cavity 2 I, mainly within the tube I1 and opening into the tube 8 throii'gh the bottom of the tube II, (Fig. 4). 26-2 "are handles by which the plunger I9 may be recip' ocated.

5II is a notch in'the lower edge of the pump handle 26, and 5| is a spring pressed pin adaptedto engage said notch to prevent an accidental raising of said handle torelease position.

The frame II is raised and lowered as follows:

The tubes 8 and I1 and pump I8 being full of oil, the plunger I9 is reciprocated by one or both of the handles 26, drawing the oil from the tube I! through the pipe l8a, and forcing it through the pipe 22 into the cavity 2| and from this through the pipe 25 into the tube 8 below the lower closed end of the tube I! thus forcing the tube l1 upward which carries with it the frame II and platform 12.

When it is desired to lower the frame II, the pin 5| is pulled outwardly against its spring pressure, thus preventing the-pin from engaging the notch 50, the plunger 19 is raised until its lower end -is above the passages 2224 as shown in Fig. 10. Then the weight of the frame II. will force the tube ll downward, the oil passing from the lower end of the tube 18 through the pipe 25, cavity 2| and passages 22-22 into the tube Referring more specificallyto Figs. 5, 6 and 7 (sheet 2). I

21 is a bevel wheel on the shaft of the wheel I 8. 28 is a bevel wheel on a vertical shaft bearing in a branch of the fork 6a and meshing with fitting into the tube Hi from the upper end of the latter and having a hub am, bearing and adapted to turn abouta vertical axis, in the outer end .of the arm [5.

22 is a shaft extending and bearing in and through the bearing 2la coaxial therewith and adapted to turn about a vertical axis. The lower end of the shaft 22 is square in cross-section. 33

is a tube square in cross-sectionupon the squared lower endof the shaft 32 and extending over' and fitting and adapted to slide upon the square portion a of the shaft of the gear wheel 20.

24 is a handle by which the shaft 22 may be rotated and 35 is a handle by which the hub 2Ia and the tube 2| may be turned. 26 is a sliding block on the handle 25 by which said handle may be locked to the stationary lug 26a, or to a ing 24a on the handle 24, or, when in an intermediate position, will leave the handle 25 free to be moved independently of the handle 24. 21 is a click to fix the block 28 in its adjusted posi The above described apparatus is operated to move and direct the horizontal motion of the scaffold in the following manner. The block v38 is first moved outward to connect the handles 24 and 25. vSaid handles are then manipulated to rotate the'tube 2| and consequently the tube II which latter carries the wheel 5 with it through the hub 8 until the wheel 5 is in the direction it is desired that it shall move. The sliding block 28 is then moved inward until the handle 25 is anchored to the lug 22a. The handle 22 is then turned which rotates the shaft 22,

.tube 22 and therethrough the squared portion ueachconstruction. .aplatformlzziaextended structions herein set forth.

between the two constructions. The upper ends of the simplified upper frame-work Ila: are united by extensible rods or tubes 28, which may support required receptacles 28 and the single standards Ix are joined by an extensible member Ill, consisting of a tube ll (Fig. 13) split at its end and a tube 42 extending into said split end. The parts of the split end of the tube ll may be pressed together by a screw", bearing in a, part extending from one split portion over the other, the end of saidscrew engaginl against said split portion. 7

Aside from the specific embodiments of the invention herein shown and described, it will be understood that numerous details of the construction may be altered or omitted without departing from the spirit and scope of the invention as disclosed and claimed, and that I do not desire to limit the invention to the exact con- 1 claim:

1. In an apparatus of the kind described, a movable base, a vertically adjustable platform supported on said base, a steering wheel forming part of the support of said base, having a vertical' arbor rotatable in a bearing in saidbase, a hollow member forming an upward extension of said arbor, amember extendingdownward from said platform into the first mentioned member adapted to slide longitudinally in the same but restrained from. turning relative thereto, and means operable from said platform for turning said member extending downward therefrom, means for rotating said wheel to move said base, an extensible. means passing axially through said members adapted to actuate said rotating means, and means operable from said platform for actuating said extensible means. i

2. In an apparatus of the kind described, a movable base, a vertically adjustable platform supported on said base, a steering wheel forming part of the support of said base, having a vertical arbor rotatable in a bearing in said base, a hollow member forming an upward extension of said arbor, a member extending downward from said platform into the first mentioned member adapted to slide longitudinally in the same but restrained from turning relative thereto, and means operable from said platform for turning. said member extending downward therefrom, means for rotating said wheel to move said base, an extensible means passing axially through said members adapted to actuate said rotating means, and means operable from said platform for actuating said extensible means, and means for binding together at will the means for turning said member and the means for actuating said rotating means.

3. In an apparatus of the kind described, a vertically movable platform, -a vertically extending tubular member below said platform, a tubularmember extending downward from said platform, fitting and adapted to slide in the first named tubular member, the lower ends of both of said tubular members being closed, and a pump at the upper end of the second named tubular member and extending into the same. having its intake communicating with the interior of the secondnamed tubular member and its discharge port communicating with the first named tubular member below the second named tubular member.

4. In an apparatus of the kind described, a vertically movable platform, a vertically extending tubular member below platform, a tubu- 15' 1 both of said tubular members being closed, a pump having a plunger at the upper end of the -second named tubular member and its discharge port communicating with the first named tubular member below the second named tubular member, and means for putting the interior of said tubular members into connection at will.

'5. In an apparatus of the kind described a vertically movable platform, a vertically extending. tubular member below said platform, a tubular member extending downward from said platform, fitting and adapted to slide in the first named tubular. member, the lower ends of both of said tubular membersbeing closed, a pump having a plunger at the upper end of the second named tubular member and extending into the same, having its intake communicating with' the interior-of the second named tubular member. and its discharge passage communicatmg with the first named tubular member below the second-named tubular member, and a passage between the interiorof said second tubular member and the first named tubular member, so

located that it shall -be closed'by said plunger during the normal travel of the same and will be v opened by said plunger passing beyond its normal travel.

6. In an apparatus of the kind described a vertically movable platform, a vertically extending tubular member below said platform, a tubular member extending downward from said platform, fitting and adapted to slide in the first named tubular-member, the lower ends of r second named tubular member and extending into the same, having its intake communicating with the interior of the second named tubular member and its discharge passage communicating with the firstnamed tubular member below the second named tubular member, a passage between the interior of said second tubular member and the first namedtubular member, so 10 located that it shall be closed by said plunger during the normal travel of the same and will be opened by said plunger passing beyond its normal travel, and a displaceable means for limiting the normal travel of said plunger. 15

7. In an apparatus of the kind described a vertically movable platform, a vertically extending tubular member below .saidplatform, a tubular member extending downward from said platform fitting and adapted to slide in the first named tubular member, the lower ends of both of said tubular members being closed, a pump having a cylinder head and plunger reciprocating therethrough at the upper end of the second named tubular member and extending intothe 25 same, a passage in said cylinder head opening from the bore in which said plunger reciprocates upon both sides of said plunger, said pump having its intake communicating with the interior of the second named tubular member and its so discharge passage cpmmunicating with said passage in the cylinder head on one side of said plunger and with the' first; named tubular member below the second named tubular member,

said passage in the cylinder head opening to the interior of said second tubular member on the opposite side of said plunger.

. DAVID R. HILLIS. 

